If the Irish Catholics didn't manage to shut us down, and the German anarchists didn't manage to shut us down, and the Pashtun tribes didn't manage to shut us down, the Muslims have no chance of shutting us down.
Easy to forget - we are somewhat used to assaults and terror attacks. They happen. Life goes on as normal.
There are just a few more muslims than there are Irish Catholics, and for all the differences that set the lot of you to fighting, the underlying, fundamental similarities are greater. Anarchists are just that, anarchists, which necessarily makes it difficult for them to engage in any serious, long-term concerted action together. I don't recollect the pashtun tribes settling in the British Isles in any great numbers.
It's also not a matter of shutting things down but of taking things over lock, stock, and barrel. The Irish Catholics aren't interested in bringing London under their political control, at least so far as I can tell. German anarchists don't have any real political sovereignity to which they could subject the UK even if that was what they wanted to achieve. If the Pashtun tribes want to subject the UK to their sovereignity - and they may very well want to - they'll have to get a leg up on it because they're nowhere's near being such a threat. That leaves the increasing masses of muslim immigrants in the UK who refuse to integrate in any meaningful way and containing any number of leaders who have expressed their intent to subject the UK to muslim sovereignity.
Abnegation in the face of such a threat isn't enlightened tolerance, it's cultural suicide.
